The ability to track and locate shipping containers within a terminal, such as a marine, rail or intermodal terminal, is critical to the operation of the terminal. When containers are brought into a marine container terminal on a truck chassis, they are typically parked in a parking spot prior to being loaded on a ship/vessel for transport. The ability to find and load or move the correct container depends on knowing, in real-time, where the container has been parked, i.e., real-time knowledge of where the container is located within the terminal.
In a normal inbound operation, a truck brings a container into the terminal. The container is sitting on a truck chassis. Typically, once in the terminal, the truck parks and then unhooks from the chassis and its container. The container and chassis is left in a numbered parking spot, and the truck leaves the facility. In other instances, the containers are off-loaded from the chassis and appropriately stacked in the shipping terminal, these off-loaded containers are commonly referred to as being “grounded”. Stacking containers, as opposed to parking a combined chassis and container, provides for greater space utilization in the shipping terminal.
In a normal outbound operation, a container is off-loaded from a vessel and placed on a chassis. The chassis with its container is pulled into a numbered parking spot and left to be picked up by an unloaded truck that comes on to the terminal to pick up a container. The truck is directed to the parking spot, hooks up to the chassis and pulls it off the terminal. In other instances, the containers will be off-loaded from the chassis and appropriately “grounded” or stacked.
Additionally, outside of normal inbound and outbound traffic the containers will occasionally be required to be moved about the terminal for various reasons. Trucks, cranes or other container handling equipment may be responsible for moving containers about the terminal. Each time a container is moved; its new location must be identified and recorded.
In almost all instances, the identification and recordation of shipping containers is done manually, using spotters who write down or enter the location into a computer terminal. As is the case with any process that involves manual input of data, a system that employs manual identification and recordation of shipping container location is plagued with errors. Additionally, the manual systems do not provide for real-time reporting of container location nor do they provide for automated direct entry of container location into the terminal's computerized operating system, referred to herein as the Terminal Operating System (TOS).
Recent developments in identifying and tracking shipping containers in a terminal setting have focused on systems that implement the use of mobile Optical Character Recognition (OCR) or Radio Frequency (RF) tagging. However, both of these types of systems are problematic. Mobile OCR only establishes location of the container after-the-fact, i.e., when the container has been parked. A system that employs RF tags is only viable if each and every container is augmented to include the tag. Invariably, such a system will be prone to fail because not all containers would be augmented with the RF tag and, as such, containers would enter the terminal that would be unidentifiable. In the same regard, the cost related to tagging each container makes such a system cost prohibitive. Additionally, since typical shipping terminals employ a high degree of ground level metal, (acting as a radio signal reflector), long or medium range RF identification becomes very problematic.
In addition to the problem of providing real-time location-identification for shipping containers at the terminal, current systems provide no automatic means to identify the container location on a vessel. While there is a fixed grid on each vessel: tier (height), cell (side to side), and bay (bow to stern), the grid is seen as relative to the dock and the grid moves as the vessel moves (with the tide and as the vessel raises or sinks with the subtraction or addition of containers). Therefore, it is difficult to get a fix on the vessel's grid.
While modem quay cranes used to load and unload vessels have a means for “knowing” or locating a container within their own frame of reference, it is difficult to match up the crane's frame of reference with the vessel's frame of reference. The crane is constantly moving, (gantry movement along the dock), so that it can get to a different bay. It is also critical to safe terminal operation to insure that vehicles and terminal personnel are not in harm's way at the landing zone (aptly referred to as the strike zone), which is the area directly below the quay crane. In most instances, unauthorized vehicles or personnel in the landing zone will trigger an alarm-notification or auto-shutdown of the quay crane operation.
In addition to locating containers on shipping vessels, another problem exists with triggering crane-mounted OCR systems, which are used to identify containers as they are placed on and removed from shipping vessels. Currently, crane-mounted OCR systems rely on the crane controller to signal the OCR system to capture images. More specifically, the OCR system relies on a system trigger, which is derived from data collected from the crane controller, to start/stop image capture. While some crane controllers have a means for providing the requisite positional data, other crane controllers are not equipped to provide this data. Even in the instance in which the crane controller is equipped to provide the positional data, many of the controllers do not readily allow for outside connection to the system or access to the data is cost-prohibitive. In addition, in many instances crane system warranties are invalidated if additional foreign equipment or devices are added to the crane system.
The crane controller's function is to run the motors, which provide for the hoist and trolley movement of the container lifting device (commonly referred to in the industry as the headblock or spreader). In certain embodiments the controller has an external data connection, through a Program Logic Controller (PLC). This connection allows for transmission, via Ethernet, wireless, serial or the like, of hoist and trolley data to a separate, non-crane computer. In order for the controller to transmit the required data to the OCR system or any other external system, it must be equipped with software that generates or collects the needed data and sends it to the PLC or other module for outside access. In certain other embodiments the controller is not readily equipped with a means for external data connection.
The OCR computer(s) use the position data to “know” when the hoisted container is in position for good OCR images. It can then begin to capture images for OCR processing. The OCR computer(s) also use the position data to control the selection, focus, and zoom of the OCR imaging devices. In this way the correct imaging device is selected and the correct zoom and focus is applied to get a good image of the container marking.
The need exists to develop a container location-identification and tracking system that characteristically has a low error rate, is economical to implement and provides real-time data. As such, the desired system will not require the shipping containers to be augmented or retrofitted with any tracking device. Additionally, the ideal system will automatically merge data with a container identification system, such as currently employed OCR based identification systems and automatically provide real-time location-identification data to the corresponding TOS. In addition, the desired system will be capable of providing detection and location-identification to containers that are either loaded on chassis (i.e., “wheeled) or “grounded”. The desired system will also provide the ability to identify the location of the shipping container onboard the vessel.
Additionally a need exists to develop a means for triggering a crane-mounted OCR system. The desired triggering mechanism should be independent of the crane controller and provide a trigger system that will work on any crane, regardless of whether the controller is equipped with an external communication means. In addition, the desired trigger system should generate a trigger as the crane moves the container through the normal container path, off or on the vessel.